Su1560 A Novel Forward-Viewing Radial-Array Echoendoscope With a New Application: Differentiation Between Ulcerative Colitis (UC) and Crohn's Disease (CD) in Colon Beyond Rectum

Abstract

A Novel Forward-Viewing Radial-Array Echoendoscope With a New Application: Differentiation Between Ulcerative Colitis (UC) and Crohn’s Disease (CD) in Colon Beyond Rectum Satimai Aniwan*, Pradermchai Kongkam, Rungsun Rerknimitr, Sombat Treeprasertsuk, Wiriyaporn Ridtitid, Phonthep Angsuwatcharakon, Pinit Kullavanijaya Internal Medicine, Chulalongkorn University, Bangkok, Thailand Background: Colonoscopy has a limited capability to distinguish Crohn’s disease (CD) from ulcerative colitis (UC). CD has a characteristic trans-mural invasion through colonic wall. Endoscopic ultrasound (EUS), the best tool at present for intestinal wall delineation, is theoretically expected to be able to differentiate between these 2 diseases. Unfortunately, the current oblique-viewing radial-array EUS has a limitation in viewing and precludes deep intubation of EUS probe into the colon beyond rectum. With a newly designed forward-viewing radial-array echoendoscope (radial Scan Ultrasonic Video Endoscope EG-530UR2 (FUJIFILM Corporation, Tokyo, Japan) and Ultrasound Processor SU-8000 (FUJIFILM Corporation, Tokyo, Japan), the scope can readily be passed to the cecum and can be used to endosonographically illustrate colonic wall. At the time of writing we believe we are the first group to use this new equipment to study its efficacy in differentiating these 2 diseases. Methods: Patients with confirmed CD and UC in King Chulalongkorn Memorial hospital, Bangkok, Thailand, from 1st August to 31st October 2012, were prospectively recruited into the study. Both colonoscopy and colon EUS were performed. The endoscopic grading of severity was assessed by Baron Index for UC, and Crohn’s Disease Endoscopic Index of Severity for CD. EUS findings of total wall (TW) thickness, muscularis proria (MP) layer thickness, irregular interface between sub-mucosa (SM) and MP layer), from the most active colonic lesions were recorded and compared between the 2 groups. Results: Twenty-seven patients (8 CD, 19 UC) were enrolled. CD patients had significantly higher TW thickness (6.4 2.5 vs. 3.4 1.0 mm; p 0.001), SM wall thickness (2.4 1.4 vs. 1.4 0.5 mm; p 0.015), and MP wall thickness (2.3 1.6 vs. 1.0 0.4 mm; p 0.003) than UC patients. Irregular interface between SM and MP layer was detected in 63% of CD patients, whereas none of the UC patients was detected. Fusion of all 5 layers was demonstrated in 2 patients with CD. Summary: The new forward-viewing radial-array echoendoscope demonstrated significantly thicker colonic wall in CD than UC. It also shows a characteristic fusion of all 5 layers in CD. Conclusion: The new forward-viewing radial-array echoendoscope is a promising tool for differentiating CD from UC. We will conduct a larger systematic study to validate the real accuracy and usefulness of this new equipment.